1 files changed, 136 insertions, 18 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8131949d10f..fdad4eeeb42 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -29,6 +29,7 @@
 #define NT_GNU_BUILD_ID 3
 #endif
 
+static void dso_cache__free(struct rb_root *root);
 static bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
 static int elf_read_build_id(Elf *elf, void *bf, size_t size);
 static void dsos__add(struct list_head *head, struct dso *dso);
@@ -343,6 +344,7 @@ struct dso *dso__new(const char *name)
                 dso__set_short_name(dso, dso->name);
                 for (i = 0; i < MAP__NR_TYPES; ++i)
                         dso->symbols[i] = dso->symbol_names[i] = RB_ROOT;
+                dso->cache = RB_ROOT;
                 dso->symtab_type = DSO_BINARY_TYPE__NOT_FOUND;
                 dso->data_type   = DSO_BINARY_TYPE__NOT_FOUND;
                 dso->loaded = 0;
@@ -378,6 +380,7 @@ void dso__delete(struct dso *dso)
                 free((char *)dso->short_name);
         if (dso->lname_alloc)
                 free(dso->long_name);
+        dso_cache__free(&dso->cache);
         free(dso);
 }
 
@@ -3008,22 +3011,87 @@ int dso__data_fd(struct dso *dso, struct machine *machine)
         return -EINVAL;
 }
 
-static ssize_t dso_cache_read(struct dso *dso __used, u64 offset __used,
-                              u8 *data __used, ssize_t size __used)
+static void
+dso_cache__free(struct rb_root *root)
 {
-        return -EINVAL;
+        struct rb_node *next = rb_first(root);
+
+        while (next) {
+                struct dso_cache *cache;
+
+                cache = rb_entry(next, struct dso_cache, rb_node);
+                next = rb_next(&cache->rb_node);
+                rb_erase(&cache->rb_node, root);
+                free(cache);
+        }
 }
 
-static int dso_cache_add(struct dso *dso __used, u64 offset __used,
-                         u8 *data __used, ssize_t size __used)
+static struct dso_cache*
+dso_cache__find(struct rb_root *root, u64 offset)
 {
-        return 0;
+        struct rb_node **p = &root->rb_node;
+        struct rb_node *parent = NULL;
+        struct dso_cache *cache;
+
+        while (*p != NULL) {
+                u64 end;
+
+                parent = *p;
+                cache = rb_entry(parent, struct dso_cache, rb_node);
+                end = cache->offset + DSO__DATA_CACHE_SIZE;
+
+                if (offset < cache->offset)
+                        p = &(*p)->rb_left;
+                else if (offset >= end)
+                        p = &(*p)->rb_right;
+                else
+                        return cache;
+        }
+        return NULL;
+}
+
+static void
+dso_cache__insert(struct rb_root *root, struct dso_cache *new)
+{
+        struct rb_node **p = &root->rb_node;
+        struct rb_node *parent = NULL;
+        struct dso_cache *cache;
+        u64 offset = new->offset;
+
+        while (*p != NULL) {
+                u64 end;
+
+                parent = *p;
+                cache = rb_entry(parent, struct dso_cache, rb_node);
+                end = cache->offset + DSO__DATA_CACHE_SIZE;
+
+                if (offset < cache->offset)
+                        p = &(*p)->rb_left;
+                else if (offset >= end)
+                        p = &(*p)->rb_right;
+        }
+
+        rb_link_node(&new->rb_node, parent, p);
+        rb_insert_color(&new->rb_node, root);
+}
+
+static ssize_t
+dso_cache__memcpy(struct dso_cache *cache, u64 offset,
+                  u8 *data, u64 size)
+{
+        u64 cache_offset = offset - cache->offset;
+        u64 cache_size   = min(cache->size - cache_offset, size);
+
+        memcpy(data, cache->data + cache_offset, cache_size);
+        return cache_size;
 }
 
-static ssize_t read_dso_data(struct dso *dso, struct machine *machine,
-                     u64 offset, u8 *data, ssize_t size)
+static ssize_t
+dso_cache__read(struct dso *dso, struct machine *machine,
+                 u64 offset, u8 *data, ssize_t size)
 {
-        ssize_t rsize = -1;
+        struct dso_cache *cache;
+        ssize_t ret;
         int fd;
 
         fd = dso__data_fd(dso, machine);
@@ -3031,28 +3099,78 @@ static ssize_t read_dso_data(struct dso *dso, struct machine *machine,
                 return -1;
 
         do {
-                if (-1 == lseek(fd, offset, SEEK_SET))
+                u64 cache_offset;
+
+                ret = -ENOMEM;
+
+                cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
+                if (!cache)
                         break;
 
-                rsize = read(fd, data, size);
-                if (-1 == rsize)
+                cache_offset = offset & DSO__DATA_CACHE_MASK;
+                ret = -EINVAL;
+
+                if (-1 == lseek(fd, cache_offset, SEEK_SET))
                         break;
 
-                if (dso_cache_add(dso, offset, data, size))
-                        pr_err("Failed to add data int dso cache.");
+                ret = read(fd, cache->data, DSO__DATA_CACHE_SIZE);
+                if (ret <= 0)
+                        break;
+
+                cache->offset = cache_offset;
+                cache->size   = ret;
+                dso_cache__insert(&dso->cache, cache);
+
+                ret = dso_cache__memcpy(cache, offset, data, size);
 
         } while (0);
 
+        if (ret <= 0)
+                free(cache);
+
         close(fd);
-        return rsize;
+        return ret;
+}
+
+static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
+                              u64 offset, u8 *data, ssize_t size)
+{
+        struct dso_cache *cache;
+
+        cache = dso_cache__find(&dso->cache, offset);
+        if (cache)
+                return dso_cache__memcpy(cache, offset, data, size);
+        else
+                return dso_cache__read(dso, machine, offset, data, size);
 }
 
 ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
                               u64 offset, u8 *data, ssize_t size)
 {
-        if (dso_cache_read(dso, offset, data, size))
-                return read_dso_data(dso, machine, offset, data, size);
-        return 0;
+        ssize_t r = 0;
+        u8 *p = data;
+
+        do {
+                ssize_t ret;
+
+                ret = dso_cache_read(dso, machine, offset, p, size);
+                if (ret < 0)
+                        return ret;
+
+                /* Reached EOF, return what we have. */
+                if (!ret)
+                        break;
+
+                BUG_ON(ret > size);
+
+                r      += ret;
+                p      += ret;
+                offset += ret;
+                size   -= ret;
+
+        } while (size);
+
+        return r;
 }
 
 ssize_t dso__data_read_addr(struct dso *dso, struct map *map,